[avr-gcc-list] Interrupt prologues

While many of us are having to hand-assemble
interrupt handlers to get around AVR-GCC's occasionally long-winded and

inefficient prologue/epilogue,

I'd been meaning to ask others about this. One of our other developers
complained of the absurdly long prologue on a simple interrupt function he'd
written which needed to check a port pin ASAP. I checked the code, and
noticed some odd things.